I am wondering what are the differences in the similar filenames, are they the same game (different versions) or what?
what the trailing characters in file name mean?
(http://forums.nesdev.com/download/file.php?id=1352&t=1)
Different dumps. For most sane people, the files marked [!] are the only ones you want.
A list of codes is here: http://en.wikipedia.org/wiki/GoodTools#Good_codes (http://en.wikipedia.org/wiki/GoodTools#Good_codes)
thank you for such prompt and accurate answer!